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Evanescent field sensors based on waveguide surfaces play an important role where high sensitivity is required. Particularly tantalum pentoxide (Ta2O5) is a suitable material for thin-film waveguides due to its high refractive index and low attenuation. Many label-free biosensor systems such as grating couplers and interferometric sensors as well as fluorescence-based systems benefit from this waveguide material leading to extremely high sensitivity. Some biosensor systems based on Ta2O5 waveguides already took the step into commercialization. This report reviews the various detection systems in terms of limit of detection, the applications, and the suitable surface chemistry.

Ethylene is a gaseous ripening phytohormone of fruits and plants. Presently, ethylene is primarily measured with stationary equipment in laboratories. Applying in situ measurement at the point of natural ethylene generation has been hampered by the lack of portable units designed to detect ethylene at necessary resolutions of a few parts per billion. Moreover, high humidity inside controlled atmosphere stores or containers complicates the realization of gas sensing systems that are sufficiently sensitive, reliable, robust and cost efficient. In particular, three measurement principles have shown promising potential for fruit supply chains and were used to develop independent mobile devices: non-dispersive infrared spectroscopy, miniaturized gas chromatography and electrochemical measurement. In this paper, the measurement systems for ethylene are compared with regard to the needs in fruit logistics; i.e. sensitivity, selectivity, long-term stability, facilitation of automated measurement and suitability for mobile application. Resolutions of 20–10 ppb can be achieved in mobile applications with state-of-the-art equipment, operating with the three methods described in the following. The prices of these systems are in a range below €10 000.

There is increasing evidence that endothelial dysfunction is involved in refractoriness of acute GvHD (aGvHD). Here we investigated the hypothesis that another endothelial complication, transplant-associated thrombotic microangiopathy (TMA), contributes to the pathogenesis of aGvHD refractoriness. TMA was retrospectively assessed in 771 patients after allogeneic stem cell transplantation (alloSCT). Incidences of TMA and refractory aGvHD were correlated with biomarkers of endothelial damage obtained before alloSCT for patients receiving or not receiving statin-based endothelial prophylaxis (SEP). Diagnostic criteria for TMA and refractory aGvHD were met by 41 (5.3%) and 76 (10%) patients, respectively. TMA was overrepresented in patients with refractory aGvHD (45.0 vs 2.3% in all other patients, P<0.001). TMA independently increased mortality. Elevated pretransplant suppressor of tumorigenicity-2 and nitrates along with high-risk variants of the thrombomodulin gene were associated with increased risk of TMA. In contrast, SEP abolished the unfavorable outcome predicted by pretransplant biomarkers on TMA risk. Patients on SEP had a significantly lower risk of TMA (P=0.001) and refractory aGvHD (P=0.055) in a multivariate multistate model. Our data provide evidence that TMA contributes to the pathogenesis of aGvHD refractoriness. Patients with an increased TMA risk can be identified pretransplant and may benefit from pharmacological endothelium protection.

Genomic sequencing projects unraveled the mutational landscape of head and neck squamous cell carcinoma (HNSCC) and provided a comprehensive catalog of somatic mutations. However, the limited number of significant cancer‐related genes obtained so far only partially explains the biological complexity of HNSCC and hampers the development of novel diagnostic biomarkers and therapeutic targets. We pursued a multiscale omics approach based on whole‐exome sequencing, global DNA methylation and gene expression profiling data derived from tumor samples of the HIPO‐HNC cohort (n = 87), and confirmed new findings with datasets from The Cancer Genome Atlas (TCGA). Promoter methylation was confirmed by MassARRAY analysis and protein expression was assessed by immunohistochemistry and immunofluorescence staining. We discovered a set of cancer‐related genes with frequent somatic mutations and high frequency of promoter methylation. This included the ryanodine receptor 2 (RYR2), which showed variable promoter methylation and expression in both tumor samples and cell lines. Immunohistochemical staining of tissue sections unraveled a gradual loss of RYR2 expression from normal mucosa via dysplastic lesion to invasive cancer and indicated that reduced RYR2 expression in adjacent tissue and precancerous lesions might serve as risk factor for unfavorable prognosis and upcoming malignant conversion. In summary, our data indicate that impaired RYR2 function by either somatic mutation or epigenetic silencing is a common event in HNSCC pathogenesis. Detection of RYR2 expression and/or promoter methylation might enable risk assessment for malignant conversion of dysplastic lesions.

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Background: Mutation of a tumor suppressor allele leaves the second as backup. Not necessarily so with p53. This homo-tetrameric transcription factor can become contaminated with mutant p53 through hetero-tetramerization. In addition, it can be out-competed by the binding to p53 DNA recognition motifs of transactivation-incompetent isoforms (ΔN and ΔTA-isoforms) of the p53/ p63/p73 family of proteins. Countermeasures against such dominant-negative or dominantinhibitory action might include the evolutionary gain of novel, transactivation-independent tumor suppressor functions by the wild-type monomer.

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